[Homeroast] Poisson's ratio WAS: Re: Compak vs Macap vs Rocky Grinders
theotherjo at gmail.com
Tue May 18 09:59:46 CDT 2010
Nice to hear a human description of a "Natural" force of nature. We being
part of nature. Although some would argue I'm not at all natural of this
earth like my mother who used to ( tongue in cheek I'm sure ) tell friends
when introducing me as a child that "Joe did not come by stork, there was
this small shiny ship that landed one night in our neighborhood." Could this
be why I love Sci fi and this black gold that runs through this list's
vein's? I did a wiki pedia and some other reading so I would have a clue
when you and RayO or anyone else shares information on this 'spro tamping
Very interesting and fun now back to my coffee.
On Tue, May 18, 2010 at 7:34 AM, Mike Koenig <koenig.mike at gmail.com> wrote:
> I'm probably splitting hairs here, but Poisson's effect happens on the
> molecular level, with bonds elongating under pressure or strain. I'm not a
> geoscience guy, but I imagine the effect effect would happen in rocks,
> clays and shale, etc, but what you are seeing in a coffee puck is
> interactions between discrete non-uniform particles.
> I'm not arguing at all that you don't get some lateral expansion during
> tamping, since that certainly does happen, but it's not necessarily
> and dependent on the distribution (and re-arrangement under force) of the
> particles, as opposed to poisson's effect, which describes a predictable
> amount of lateral expansion based on the change axial length. If the
> expansion was due to poisson's effect, the puck would spring back when you
> let go of the tamper. What you are getting is some re-arrangement of the
> particles under force (like when you step in sand, and it moves out of the
> way under your foot).
> On Tue, May 18, 2010 at 3:01 AM, <raymanowen at gmail.com> wrote:
> > Then I don't know why the grounds would press out and seal against the
> > sides
> > of the basket when you are only applying axial force with the tamper.
> > Hydrostatic?
> > I hope I don't owe a refund of all our pay at the Geophysics Research
> > Institute at CSM. Please don't tell Dr. Levent Ozdemir or Dr. Russ Miller
> > we
> > were doing bad oil shale research. Damn!
> > What supports you when you walk on a sandy beach?
> > Teach me, please. -ro
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